texi2html: Add check for directory existence

Without this, if configure fails, it won't be able to run again as the directory
already exists.

(From OE-Core rev: 71a3ba536d022eea3a199cf4d6c5c791d91603a0)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/recipes-extended/texi2html/texi2html_5.0.bb

@@ -16,7 +16,9 @@ inherit autotools gettext
 
 do_configure_prepend() {
 	# Make a directory for the old gettext setup
-	mkdir ${S}/po
+	if [ ! -d ${S}/po ]; then
+		mkdir ${S}/po
+	fi
 }
 
 do_configure_append() {